That's why when Mackenzie Crawford's deteriorating condition caused him to take a horrific fall, his friends knew they wanted to help.

Jacob Wilson says "When Mackenzie fell down the stairs and broke his arm and I wanted to do something, we decided to set up a bike-a-thon."

Without hesitation the boys went to work planning with the help of their parents.

Truman Keys says "I knew someday we had to do something, but a while back, I didn't think it was necessary, but now I think it needs to be done. I think as the disease progresses it gets harder for him."

Mackenzie Crawford says "To walk up stairs and walk long distances."

And that has been hard for Mackenzie's parents to watch.

Paula Crawford, Mackenzie's Mom says "It's hard to seeand he will come in because he knows he has reached his limit, but his friends are still going strong outside."

With Duchenne the simplest of tasks become difficult and in the later stages, heart and breathing muscles begin to fail. This disease is rare, there are approximately 20,000 boys across the country living with Duchenne, and while most of them are in a wheelchair by age 12, Mackenzie is beating the odds.

He is a typical 13-year-old full of life, who enjoys being with his friends.

Both Mackenzie and his family are grateful for his special friends.

Paula Crawford says "It has really touched our heartsand they are really a blessing for Mackenzie to have."

And though he's a young man of few words, Mackenzie says he wouldn't trade his friends for anything in the world. This life threatening situation has brought them all closer and made their bond just that much stronger.

Mackenzie Crawford says "Thank you for putting a bike-a-thon together."

No thanks necessary. The only reward these guys want is to raise a lot of money and help find a cure so their best friend can get better.